Sydney Opera House architect dies

The mastermind behind the iconic Sydney Opera House has died at age 90.

Danish architect Joern Utzon died from a heart attack in his sleep in Denmark on Saturday.

"He had not been doing well these past few days, since Thursday. He had been undergoing a series of operations recently," his son, Kim Utzon, told The Associated Press.

Utzon designed the opera house in 1957. He quit the project in 1966, seven years before it was completed, after arguments over design and cost arose.

The interior was never completed to Utzon's original plan, but he still managed to scoop the Pritzker Architecture Prize in 2003 for his work.

Utzon won a competition to design the opera house.

He also designed the National Assembly building in Kuwait City.

"In the great sweep of history, what we're left with is a beautiful building, Sydney's symbol to the world, Australia's symbol to the world and owed in large part to this great man - a son of Denmark but I've got to say in terms of his spirit, a son of Australia as well," Australian Prime Minister Kevin Rudd said in a statement